关键词: 天麻, 抗真菌蛋白

Abstract: An anti-fungal protein named GAFP was isolated and purified from the terminal corm of Gastrodia elata Bl. 4 p-g of this protein impregnated in a paper disc on potato glucose agar medium inhibited obviously mycelial spread of Trichoderma reessei, About 20 mg of GAFP was obtained from 1 kg of fresh corm. Only the external part of corm contains this protein, whereas no GAFP was detected in inner part of corm. SDS-PAGE and gel filtration on sephadex G50 showed that GAFP is a single polypetide with MW=14.0 kD, and pI =8.1, determined by binding test of the protein on SP-Sephadex C50. The protein is rich in Asn, Gly, Ala and Leu, but lacks Met, Pro and Cys. GAFP can not give colour reaction with Coomassie blue reagent except that the protein is dena-tured by heat or SDS treatment. It was shown not to be of exochitinase and β-1, 3-glucanase activity. GAFP is thought to play an important role in the defense mechanism of the yearly terminal corm to prevent the infection of fungi.

Key words: Gastrodia elata